1. Field of the Invention
The present invention relates to an aluminum alloy and a manufacturing method thereof.
2. Description of the Related Art
Magnesium (Mg) is currently one of the main alloying elements in an aluminum (Al) alloy. The addition of Mg increases the strength of aluminum alloy, makes the alloy favorable to surface treatment, and improves corrosion resistance. However, there is a problem that the quality of a molten aluminum may be deteriorated due to the fact that oxides or inclusions are mixed into the molten aluminum during alloying of magnesium in the molten aluminum because of a chemically high oxidizing potential of magnesium. In order to prevent oxides or inclusions from being mixed into the molten aluminum due to the addition of magnesium, a method of covering the melt surface with a protective gas such as SF6 may be used during the addition of magnesium.
However, it is difficult to perfectly protect magnesium, which is massively added during the preparation of an aluminum alloy, using a protective gas. Furthermore, SF6 used as the protective gas is not only an expensive gas but also a gas causing an environmental problem, and thus the use of SF6 is now being gradually restricted all over the world.